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Letter| Volume 19, ISSUE 3, P159-160, March 2000

Paradoxical Response to Radiotherapy in Malignant Spinal Cord Compression

      To the Editor:
      Spinal cord compression (SCC) develops in almost 5% of patients with advanced cancer and is usually caused by epidural metastasis. SCC also can be produced by leptomeningeal or intramedullar metastases, or even by primary spinal neoplasms.
      • Byrne T.N.
      Spinal cord compression from epidural metastases.
      When suspected, MRI is the procedure of choice in the diagnostic work-up. Accepted standard of therapy consists of radiation therapy and/or surgery.
      • Graus F.
      Spinal cord compression in cancer patients.
      • Loblaw A.
      • Lapierre N.J.
      Emergency treatment of malignant extradural spinal cord compression an evidence-based guideline.
      Radiotherapy is the most frequent treatment; surgery is preferred for children, patients without pathologic diagnosis of malignancy, spinal instability, tumors resistant to radiotherapy, or SCC in previously irradiated sites. Either surgery or radiotherapy may achieve a favorable outcome if performed promptly after diagnosis and in patients with a good level of neurologic function when treatment is started.
      • Fuller B.G.
      • Heiss J.
      • Oldfield E.H.
      Spinal cord compression.
      Some patients may be resistant to therapy but it is rare that active and otherwise uncomplicated therapy (without acute myelitis or bleeding, etc.) produces any acute deleterious effect on neurologic signs. We present a young patient with metastatic sarcoma who developed paradoxical neurologic worsening to palliative radiotherapy for SCC.

      Case Report

      A 28-year-old man developed progressive weakness in both legs over a two-month period. Neurologic evaluation confirmed a subacute spinal cord compression. MRI showed a retroperitoneal mass and multiple bone lesions consistent with metastases. An epidural mass compromised the spinal canal at T7. The patient received high-dose steroid therapy without neurologic improvement and an urgent diagnostic and therapeutic T7–T9 laminectomy was performed. Neurologic signs slightly improved.
      Biopsy confirmed an undifferentiated tumor. Immunohistochemistry assay was positive for vimentin (+++); all other markers were negative. An undifferentiated sarcoma was diagnosed.
      The patient received chemotherapy for three months. In order to administer the full dose intensity of chemotherapy, spinal radiotherapy was delayed. No objective response achieved and he developed progressive neurologic deterioration.
      A new MRI confirmed SCC at T7 and suggested leptomeningeal tumor (Figure 1). Palliative radiotherapy was delivered from T6–T9 (30 Gy in ten fractions). As radiotherapy was administered, his neurologic signs worsened, with increased weakness, ataxia, and hypesthesia. There was no response to higher doses of steroids and a second decompressive surgery was performed. At surgery, a tumoral ring involving and compressing the spinal cord was evidenced. The cord was liberated. Pathology showed scarce foci of viable tumor cells within fibrous tissue.
      Figure thumbnail gr1
      Fig. 1A lepotmeningeal ring (head arrows), probably tumoral, is involving and compressing spinal cord, inducing evident deformity. An altered signal secondary to first laminectomy is observed (arrow)
      Neurologic function recovered and the patient was able to walk. Later, metastatic bone pain in the sacrum, scapula, femur and base of the skull was successfully alleviated at different times with elective palliative radiotherapy. Thirteen months after the second surgery, the patient developed a slow tumor progression, but remained able to walk. Pain has been adequately managed with nonopioid and opioid analgesics.

      Comment

      The most frequent cause of SCC in cancer patients is an epidural neoplasm arising from bone metastasis. The presence of metastases in the leptomeningeal space is less common. Our patient had a mixed SCC: initially epidural and later leptomeningeal. When symptoms appeared several months after the first surgery, we assumed that there was progression of the epidural mass. However, leptomeningal compromise was observed on MRI. Clinical deterioration appeared during and after radiotherapy, and a second decompressive surgery was needed to release the cord from annular constriction.
      • Makris A.
      • Kunkler I.H.
      Controversies in the management of metastatic spinal cord compression.
      A few foci of tumor cells within fibrosis were found in the compressing ring, compatible with partial response to the previous radiotherapy (30 Gy). Thus, the patient appeared to have deteriorated as a result of a paradoxical response: as the tumoral ring became fibrous, it narrowed and further compressed the spinal cord.
      Surgery has been suggested for the pediatric tumors that invade the spinal canal via the neural foramen and compress the spinal cord in a circumferential manner.
      • Klein S.L.
      • Stanford R.A.
      • Muhlbauer M.S.
      Pediatric spinal epidural metastases.
      Our case suggests that surgery should be considered to palliate neurologic deterioration in any case of SCC secondary to annular constriction.

      References

        • Byrne T.N.
        Spinal cord compression from epidural metastases.
        N Engl J Med. 1992; 327: 614-619
        • Graus F.
        Spinal cord compression in cancer patients.
        Med Clin (Barc). 1997; 109: 373-374
        • Loblaw A.
        • Lapierre N.J.
        Emergency treatment of malignant extradural spinal cord compression.
        J Clin Oncol. 1998; 16: 1613-1624
        • Fuller B.G.
        • Heiss J.
        • Oldfield E.H.
        Spinal cord compression.
        in: de Vita V.T. Hellman S. Rosenberg S.A. Cancer. Principles and practice of oncology;. 5th edition. Lippincott-Raven, Philadelphia1997: 2476-2486
        • Makris A.
        • Kunkler I.H.
        Controversies in the management of metastatic spinal cord compression.
        Clin Oncol. 1995; 7: 77-81
        • Klein S.L.
        • Stanford R.A.
        • Muhlbauer M.S.
        Pediatric spinal epidural metastases.
        J Neurosurg. 1991; 74: 70-75